Connector for implantable prosthetic devices



NOV. 12, 1968 A, ow z ET AL 3,409,913

CONNECTOR FOR IMPLANTABLE PROSTHETIC DEVICES Filed July 1. 1966 ARTHURR. KANTROWITZ' ROBERT T. JONES RICHARD G, PRIEBE INVENTOR.

13% D F A WM 5% ATTORNEYS United States This invention relates toimplantable prosthetic devices and more particularly to means forconnecting artificial graft sections and the like to implantableprosthetic devices such as blood pumps.

The advent of open heart surgery has presented to the medical professionthe opportunity of repairing damaged or diseased hearts of individualsand where appropriate using circulatory assist systems in individualswho without such correction and/or systems face premature death. Manydevices are involved in this type of surgery. For example, onecirculatory assist system may comprise an auxiliary ventricle orvalveless blood pump connected across the arch of the aorta and drivenby fluid pressure in response to electronic signals (QRS wave) providedby the heart itself. By operating the auxiliary ventricle in properphase, the systolic pressure in the left heart can be reduced and thesystemic circulation can be maintained with a substantially reduced workload on the heart muscle. In addition, the operation of the auxiliaryventricle has the effect of shifting the phase of the normal systolicpressure so that this pressure appears in the aorta at a time when theleft ventricle is relaxed. Assuming competence of the normal aorticvalve, one then has an increased perfusion pressure available to thecoronary arteries. It is believed that such an increase in coronaryperfusion, together with a reduction in the efiort required from theheart, should be effective in a number of cases of cardiacinsufficiency.

As may be seen from the above, one important component of circulatoryassist systems is a pump that either assumes the hearts role of pumpingblood or which reduces the work load of the heart muscle. By using heartpump equipment for extended periods of time, it is contemplated that theequipment may be utilized for regional perfusions in therapeutictreatment of the heart. Still other use of the equipment will be toprovide circulation of blood through an artificial organ such as anartificial kidney. In connection with this function of the apparatus, itshould be noted that many research institutions at this time areconcentrating their research activities on providing artificialcounterparts of other organs and whenever such application requirescirculation, the present invention may be utilized.

Implantable prior art pulsatile pumps usually consist of a flexible bulbor ventricle squeezed by pressurized fluids and coupled to one or moreblood vessels such as arteries or veins. Generally, arterial graftsections connect the bulb to the circulatory system. These arterialgraft sections are generally of the woven Teflon-type or Dacron-typeemployed in the insertion of arterial grafts and the replacement ofdamaged sections of an artery.

Heretofore in such prior art pumps, the manner in which the pump wasfabricated resulted in one or more of the following disadvantages:Minimum contact surface between the tissue which grows on the graftmaterial and the bulb on which tissue will not grow, failure of the bulband/or unsatisfactory growth of tissue at the junction of the graftmaterial and the bulb. Unsatisfactory growth of tissue is believed toinclude insuflicient blood flow in the tissue after it has formed,growth in such a manner as to result in injury to the blood (heatcnt Omolysis) and/or free forming clots or clots which break off and arecarried away by the blood steam. Accordingly, a feature of th presentinvention is the provision of a connector in an implantable prostheticdevice connected to the circulatory system'which has improved clottingcharacteristics.

Another feature of the invention is the provision of a connector whichprovides maximum area of contact between tissue growth in an arterialgraft section and a material acceptable to the blood but on whichtissue'will not grow.

Another feature of the invention is the provision of a connector whichnot only provides maximum area of contact between tissue growth in anarterial graft section and a material acceptable to the blood but onwhich tissue will not grow, but which also permits normal blood flow inand through such tissue growth after it has formed.

A further feature of the inv ntion is the provision of a connector whichincreases the life and dependability of a connection between a graftsection and an elastomer material.

The novel features that are considered characteristic of the presentinvention are set forth in the appended claims; the invention itself,however, both as to its organization and method of operation togetherwith additional objects and advantages thereof, will best be understoodfrom the description of a specific embodiment when read in conjunctionwith the accompanying drawings, in which:

FIGURE 1 is a perspective view with parts broken away of an implantableprosthetic device comprising an auxiliary ventricle incorporating thepresent invention;

FIGURE 2 is a side view with parts broken away of a connector inaccordance with the present invention; and

FIGURE 3 is an end view taken on line 33 of FIG- URE 2.

Directing attention now to FIGURE 1, there is shown by way of example avalveless auxiliary ventricle generally designated by the numeral 10,incorporating the present invention. While the present invention will,for convenience, be described in connection with an auxiliary ventricle,it is to be understood that if may be used in conjunction withprosthetic devices, plastic tubes and the like adapted for connection tothe circulatory system.

The auxiliary ventricle as shown in FIGURE 1 is adapted for implantationwithin a living body. Arterial graft sections 11 and 12 are attached tothe open ends of the auxiliary ventricle by connector means more fullydescribed hereinafter. For the type of auxiliary ventricle shown, thearterial graft sections 11 and 12 generally are surgically attached tothe aorta (not shown) in conventional manner. The arterial graftsections may be of the well known woven Teflon-type employed in theinsertion of arterial grafts and the replacement of damaged sections ofan artery. Edwards Seamless Arterial Graft manufactured by the UnitedStates Catheter and Instrument Company have been found to besatisfactory.

The auxiliary ventricle is comprised of an elongated and compliant bulb13 having two openings 14 and 15 to permit blood to freely flowtherethrough. The aforementioned arterial graft sections are attached tothe auxiliary ventricle at these openings. The bulb may be comprised ofa flexible material acceptable to the blood, such as for example MedicalSilastic 372 supplied by Dow Corning Corporation, Midland, Mich. Thebulb may have a generally ellipsoidal configuration or alternately, havea generally U-shaped configuration as shown in FIG- URE 1. The bulb hasa capacity suflicient to receive an appreciable fraction of the outflowfrom the left ventricle of the heart and is shaped to provide optimumflow conditions and minimum stresses during use.

Surrounding and sealably connected to the bulb 13 at its open ends is arigid and air tight case 16 including a pressure conduit 17 coupledthereto for transmit-ting pulses of a fluid or a gas, such as forexample oxygen, to the region between the bulb 13 and the case 16.Connector means generally designated by the numerals 21 and 22 attachthe arterial graft sections to the auxiliary ventricle. Connector meansin accordance with the present invention now to be described in detailattaches the arterial graft sections to the auxiliary ventricle in a newand novel manner and in its preferred embodiment provides an air tightseal between the bulb and the case.

Directing attention now to FIGURES 2 and 3, there is shown a connectorin accordance with a preferred embodiment of the present inventioncomprising a rigid hollow cylindrical inner member 31 sealably attachedas by bonding or potting it to the portion of the case 16 surrounding anopening in the bulb 13. The extreme end 32 of the inner member 31 remotefrom the case 16 is provided with a continuous smooth curved end surface33 preferably in the form of an outwardly extending lip 34 andintermediate its end portions, the inner member 31 is also provided withan outwardly projecting annular ring 35 threaded to receive a rigidcylindrical outer member 36 more fully described hereinafter. Theportion of the bulb defining an open end extends through the innermember 31 and over, around and past the aforementioned curved endsurface 33 to form a cuff 37. The cuff 37 is preferably sealablyattached to the outer surface of the inner member by both a suitableadhesive and by wrapping and tying it with thread 38 such as Dacronthread or the like adjacent threaded ring 35.

The provision of the cuff 37 formed by the end portion of the bulbdisposed over continuously curved end surface 33 is particularlyadvantageous in that it essentially eliminates the possible of failureof the bulb as by fatigue at or adjacent its junction with the caseand/or inner member 31.

Disposed over the cuff 37 formed by the end portion of the bulb is anarterial graft section 39 which is preferably also tied and bonded tothe cuff adjacent threaded ring 35. Directing attention now to thecylindrical outer mem ber 36, it will be noted that it surrounds innermember 31 and is adapted for threaded engagement with threaded ring 35to facilitate assembly of the connector. Integral with that portion ofthe outer member 36 remote from the case 16 is an inwardly extendingring-like member 41 the radial dimension of which is suflicient to atleast substantially cover lip 34 and permit a cloth-like filler material42 having a large number of interstices, such as for example a shortpiece of arterial graft section having a diameter slightly greater thanthat of graft section 39 and comprising several layers, to be grippedbetween ring 41 and cuff 37. A plurality of openings 43 are provided inthe outer member 36 adjacent ring 41 to permit blood to pass from theinterior of the arterial graft section to and through the fillermaterial 42 at the junction of the arterial graft section 39 and cuff37.

The inner and outer members 31 and 36 may be composed of surgicallyimplantable stainless steel, such as for example 303 or 316 stainlesssteel, dipped in silicone resin prior to assembly to provide a coatingof about /2 to 1 mil in thickness. V

After the arterial graft section 39 has been attached to inner member31, the filler material 42 preferably comprising several layers isdisposed within the outer member at ring 41. The outer member 36 is thenslipped over the arterial graft section and threaded onto the innermember 31 to compress the filler material 42 to a point wheresubstantially maximum contact is provided between the filler material42, ring 41 and that portion of the arterial graft section 39 coveringthe extreme end of cuff 37. A suitable adhesive 44 such as Silastic maybe provided at threaded ring 35 to provide a seal at this point and tohold ring 36 in place. A high compression connection is neithernecessary nor desirable as it will result in excessive restriction ofblood flow in and through the filler material and any tissue whichsubsequently forms in this region. While the number and type of openings43 provided in outer member 36 is not critical, it is recommended thatat least a substantial portion of the outer periphery of the fillermaterial 42 be exposed to permit maximum perfusion of blood through thetissue which subsequently forms in and around the filler material 42.

Having described a preferred embodiment of the invention, what isclaimed is:

1. In apparatus for receiving blood from a blood vessel such as anartery or vein in a living body and having a medically inert inner linerexposed to said blood and open at at least one end and a substantiallyinflexible case surrounding said liner, the combination comprising:

(a) an arterial graft section;

(b) connector means attached to said case and surrounding at least partof the portion of said liner defining said open end for attaching saidgraft section to said case, said connector means surrounding a portionof said graft section and having a plurality of openings adjacent itsjunction with said graft section; and

(c) perforate means disposed within said connector means at its junctionwith said graft section for providing a large number of interstices of asize to promote clotting.

2. In apparatus for receiving blood from a blood vessel such as anartery or vein in a living body and having a medically inert inner linerexposed to said blood and open at at least one end a substantiallyinflexible case surrounding said liner, the combination comprising:

(a) perforate cylindrical cloth-like material comprising an arterialgraft section;

(b) cylindrical connector means attached to said case and surroundingthe portion of said liner defining said open end for attaching saidgraft section to said case, said connector means surrounding a portionof said graft section and having a plurality of openings adjacent itsjunction with said graft section; and

(c) perforate means disposed within said connector means at its junctionwith said graft section for providing a large number of interstices of asize to promote clotting, said perforate means comprising a cloth-likematerial in communication with said openings and said graft section.

3. The combination as defined in claim 2 wherein said connector meansincludes a rigid cylindrical outer member having a first portion remotefrom said graft section I and a second portion surrounding a portion ofsaid graft section, the end of said second portion remote from saidfirst portion extending inwardly to define a circular surface in contactwith said graft section and having a diameter less than that of saidfirst portion, and said openings are disposed adjacent said circularsurface.

4. The combination as defined in claim 3 wherein the portion of saidliner defining said opening extends through said connector means andbetween said connector means and said perforate means.

5. In apparatus for receiving blood from a blood vessel such as anartery or vein in a living body including a flexible bulb exposed tosaid blood and open at at least one end and a substantially inflexiblecase surrounding said bulb, the combination comprising:

(a) an arterial graft section; and

(b) connector means sealably attached to said case and surrounding theportion of said bulb defining said open end for attaching said bulb andsaid graft section to said case, said connector means being in sealingcontact with said bulb and providing a large number of interstices of asize to promote clotting within said connector means adjacent thejunction of said connector means and said graft section, said connectormeans having a plurality of openings adjacent said junction with saidgraft section whereby blood can pass through said connector meansadjacent said junction.

6. -In apparatus for receiving blood from a blood vessel such as anartery or vein in a living body and having a medically inert flexiblebulb exposed to said blood and open at at least one end and asubstantially inflexible case surrounding said bulb, the combinationcomprising:

(a) a generally cylindrical arterial graft section;

(b) cylindrical connector means sealably attached to said case andsurrounding the portion of said bulb defining said open end forattaching said bulb and said graft section to said case, said connectormeans including a cylindrical outer member surrounding an inner member,said inner member being in contact with and surrounding the portion ofsaid bulb defining said opening, said portion of said bulb extendingover and around the end of said inner member remote from said case, theend of said outer member remote from said case extending inwardly todefine a circular surface and having a plurality of openings adjacentsaid surface; and

(c) perforate means carried by said outer member and in communicationwith said openings and said graft section, said perforate means having alarge number of interstices of a size to promote clotting.

7. In apparatus for receiving blood from a blood vessel such as anartery or vein in a living body and having a substantially inflexiblecase and a medically inert flexible bulb disposed Within said case andexposed to said blood, said bulb having at least one portion defining anopening and extending through said case, the combination comprising:

(a) perforate cloth-like material comprising "a generally cylindricalarterial graft section;

(b) cylindrical connector means attached to said case and surroundingsaid portion of said bulb defining said opening for attaching said graftsection to said case and sealably attaching said bulb to said case, saidconnector means including a cylindrical outer member surrounding aninner member integral with said case, said inner member being in contactwith and surrounding said portion of said bulb defining said opening,said portion of said bulb extending over and around the end of saidinner member remote from said case, the end of said outer member remotefrom said case extending inwardly to define a circular surface spacedfrom said inner member and having a plurality of openings adjacent saidsurface; and

(c) penforate means carried by said outer member and in communicationwith said openings and said graft section, said perforate means having alarge number of interstices of a size to promote clotting.

8. The combination as defined in claim 7 wherein the said end of saidinner member defines a smooth curved surface and said bulb is maintainedin sealing contact with the outer surface of said inner member.

9. The combination as defined in claim 8 wherein said smooth curvedsurface defines an outwardly extending lip.

'10. The combination as defined in claim 7 wherein said perforate meanscomprises a cloth-like material disposed between the said portion ofsaid bulb extending around the end of said inner member and saidcircular surface space from said inner member.

11. The combination as defined in claim 10 wherein said graft sectionextends between the said perforate means and the said portion of saidbulb extending around the end of said inner member.

12. In apparatus for augmenting blood flow (from a heart in a livingbody including a flexible bulb open at both ends and a substantiallyinflexible case surrounding said bulb intermediate its open ends, thecombination comprising:

(a) a rigid, hollow, cylindrical inner end member sealably attached torespectively each end of said case;

(b) an outwardly extending lip integral with the extreme end of eachsaid inner member remote from said case, each said lip defining a smoothgenerally cylindrical surface connecting said inner and outer surfacesof said inner member, the end portions of said bulb extending throughsaid inner members and being disposed over said lips to form a cuff;

(0) means for sealably attaching the end portions of said bulb to theouter surface of each said inner member rearwardly of said lips;

(d) an arterial graft section having one end disposed over andsurrounding respectively each said cuff;

(e) a rigid cylindrical outer end member carried by and surrounding eachsaid inner member, the end of said outer member remote from said caseextending past said inner member and inwardly to define a smoothcircular surface spaced from said inner member and having a plurality ofopenings adjacent said surface; and

( f) a plurality of thicknesses of a cloth-like material disposedbetween said |graft sections surrounding said cuffs and said circularsunfaces, said cloth-like material having a large number of intersticesof a size to promote clotting and being in communication with saidopenings in said outer members.

References Cited UNITED STATES PATENTS 2,978,262 4/1961 Franck 2852483,007,416 11/1961 Childs 103-44 3,097,366 7/1963 Winchell 3-1 3,152,34010/1964 Fryetal 3--1 3,357,432 12/1967 Sparks 128-334 3,380,764 4/1968Wilson 285249 OTHER REFERENCES Prolonged Ventricle Bypass WithIntrathoracic Pumps by D. Liotta et al., Transactions A.S.A.I.O., vol.X, June 19, 1964, pp. 154-156.

Problems In Calf Lungs Immediately After Implantation of An ArtificialHeart by T. Akutsu et al., Transactions A.S.A.I.O. vol X, June 19, 1964,pp. 162-165.

Successful Hemodynamic Results With A New U- shaped Atuxiliary Ventricleby F. Gradel et al., Transactions A.S.A.I.O., June 19, 1965, pp.277-283.

Booster Pump Gives New Life to Failing Hearts by C. P. Gilmore, PopularScience, December 1965, pp. 48-51 and 194.

RICHARD A. GAUDET, Primwry Examiner.

RONALD L. FRINKS, Assistant Examiner.

1. IN APPARATUS FOR RECEIVING BLOOD FROM A BLOOD VESSEL SUCH AS A ARTERYOR VEIN IN A LIVING BODY AND HAVING A MEDICALLY INERT INNER LINEREXPOSED TO SAID BLOOD AND OPEN AT AT LEAST ONE END AND A SUBSTANTIALLYINFLEXIBLE CASE SURROUNDING SAID LINER, THE COMBINATION COMPRISING: (A)AN ARTERIAL GRAFT SECTION; (B) CONNECTOR MEANS ATTACHED TO SAID CASE ANDSURROUNDING AT LEAST PART OF THE PORTION OF SAID LINER DEFINING SAIDOPEN END FOR ATTACHING SAID GRAFT SECTION TO SAID CASE, SAID CONNECTORMEANS SURROUNDING A PORTION OF SAID GRAFT SECTION AND HAVING A PLURALITYOF OPENINGS ADJACENT ITS JUNCTION WITH SAID GRAFT SECTION; AND (C)PERFORATE MEANS DISPOSED WITHIN SAID CONNECTOR MEANS AT ITS JUNCTIONWITH SAID GRAFT SECTION FOR PROVIDING A LARGE NUMBER OF INTERSTICES OF ASIZE TO PROMOTE CLOTTING.